Drilling apparatus



March 24, 1959 c. v. TILDEN DRILLING APPARATUS Filed April 29, 1957 FIG.2.

I N VEN TOR.

' men/5y N f m w A 2 m venient means such as a portable suction cleaner.

DRILLING APPARATUS Carl V. Tilden, Capistrano Beach, Calif.

Application April 29, 1957, Serial No. 655,559

? 7 Claims. 01. 255-50) This invention relates to drilling apparatus fordrilling holes in hard rock and the like and more particularly to animproved core drill incorporating simple but effective provision for theremoval by air of cuttings.

that these cuttings be flushed away from the base of the bore and it hasbeen common practice to feed water "to the drill head .for the purposeof carrying away the cuttings in the space surrounding the drill barrel.While water is efiective for the purpose a source of pressurized wateris not always available. Furthermore, the discharging stream of Water isnot readily controlled and, in many instances, the use of water cannotbe tolerated as for example where the drilling is to be carried oninside a building or dwelling. Attempts to use air as the flushingmedium have also been made but these require the use of motor-drivencompressors. Furthermore, large quantities of dust and fine cuttingsissuing from the bore are likely to be breathed by the drill operatorunless precautions are taken to wear a face mask. Additionally fine dustis deposited about the surrounding area which is objectionable. Suctiondevices heretofore provided for clearing away the dust and fine cuttingshave been unsatisfactory, cumbersome, unreliable, and have interferedobjectionally with the operation and manipulation of the drill proper.

These and other serious objections applicable to prior devices areentirely overcome by the present invention which contemplates theprovision of a simple core drill readily separable into a few essentialcomponents and preferably held together by friction joints. Essentially,

away cuttings in a suction airstream provided by any con- To this endasuction hose connected with the cleaner includes a hood fitting looselyabout the shank of the drill and enclosing the exposed outer end of thecore barrel, the rim portion ofthe hood being held sealed 'against therim of a bushing member journaled on the core barrel at the rim of thebore. When the drill is not in operation and the suction source isde-energized all parts of the drill including the suction hood arereadily separable. The bushing referred to above serves severalimportant functions including those of centering the drill in the bore,assuring a supply of flushing air to the bore and providing a supportfor the resilient lip of the suction hood.

Accordingly, it is the primary object of the present invention toprovide an improved drill for use in drilling hard brittle materials andincorporating effective and eflicient means for flushing away the drillcuttings to a p collecting receptacle.

i United States Patent ce Patented Mar. 24, 1959 2 Another object of theinvention is the provision of an improved core drill having meanscarried loosely thereon for assuring an air supply into the bore andproviding asupport for a readily detachable suction conduit carryingaway cuttings.

Another object of the invention is the provision of a core drill havingportable suction means for collecting the drill cuttings and including aflexible suction hose held coupled by suction to a bushing journaledabout the core drill as long as the suction meansis operating.

These and other more specific objects will appear clearly upon readingthe following specification and claims and upon considering inconnection therewith the attached drawing to which they relate.

' the drill of this invention features a device for carrying Referringnow to the drawing in which 'a preferred embodiment of the invention isillustrated: I

Figure 1 is a view in side elevation of a drilling apparatusincorporating the present invention assembled in readiness for use; and

Figure 2 is a longitudinal sectional view on an enlarged scale throughthe drill proper.

In Figure 1 there is shown a drilling apparatus designated generally 10and comprising as major components a portable electric driving motor 11,a drill assembly 12 and a portable source of air suction such as acanistertype suction cleaner 13. The drill head 12 preferably comprisesa tubular core barrel 15 provided with tapered ends 16 and .17 having aclose frictional fit with a cutting head assembly 18 and an end cap 19.Cutting head assembly 18 includes a ring 20 having a plurality ofcutting teeth 21 brazed or otherwise securely fixed thereto. The teethillustrated are diamond shaped in crosssection andjproject slightlybeyond the inner and outer surfaces of ring 20 for the purpose ofcutting an annular ring of greater width than the thickness of thecutter head. This assures that the drill will not bind either againstthe side wall of the bore or against the core extending centrally intothe core barrel.

End cap 19 has a flaring inner rim 23 forming a driving friction fitwith tapered end 17 of the barrel. Projecting axially from end cap 19and fixed thereto by threads 25 is a driving shank 24 the outer end ofwhich is shaped to be detachably clamped in a chuck 26 carried by theshaft of the portable driving motor 11. Cap 19 has a number ofperforations 27 providing for the passage of a flushing medium as willbe described more fully presently.

Looselyjournaled about the exterior of core barrel 15 is a bushing 30which is longitudinally displaceable on the drill between cutting head18 and end cap 19, it being understood that the exterior diameters ofthe cutting head and the end cap are slightly greater than the internaldiameter of the bushing. Bushing 30 has a thin-walled cylindrical skirtsecured at its outer rim to a radial flange 31. Suitable means, such asribs 32, project from the surface of flange 31 facing toward the skirtand may extend along the latter to support the bushing in spacedrelation to the adjacent wall portions of the material 45 being drilled.Additionally and importantly, these ribs provide flow passages foradmitting a flushing fluid downwardly into 'the bore about the exteriorof the drill.

The means for flushing away and collecting the cuttings produced by theoperation of the drill comprises any simple and suitable suction sourceconveniently provided by a suction cleaner such as the canister-typegenerally indicated at 13 in Figure 1. This cleaner comprises a casing;35 housing a multiple-stage high-suction fan at one end and a filter bagat the other. The removable end cap 36' of the cleaner casing serves toclamp the filter bag in place and to conduct a cutting-laden airstreaminto the filter bag, the clean air escaping through the bag wallspassing into the suction fan from which it is exmay be made of anysuitable material, but preferably from soft resilient material such asrubber or plastic. The hood is generally cup shaped and its rim edge maybe grooved at 44 to provide a pair of flexible annular lips 42, 43having tapering edges formed to seal against the outer surface ofbushing flange 31. Groove 44 may contain a soft sponge rubber gasketprotruding slightly beyond the rim edges of lips 42 and 43. As isclearly illustrated in Figure 2, the interior diameter of the suctionhood is large enough to fit freely over the end of the drill assemblyand to provide a seal with bushing 30 in all operating positions of thedrill. Since this may require a suction hood of considerable axiallength when using longer core barrels, it is desirable to reinforce thehood against collapse by the pressure difference across its walls. Forthis purpose the hood may have imbedded therein suitable reinforcingsuch as wire rings or a wire helix 48.

The operation of the described rock drill apparatus will be apparentfrom the foregoing description of its simple components. The drill iseasily and quickly assembled by pressing end cap 19 and cutting head 18over tapered ends 16 and 17 of core barrel 15. Suction hood 39 is thenassembled over the end of shank 24 and the latter is clamped withinchuck 26 of driving motor 11. Upon completion of the power supply tomotor 11 and the closing of switch button 49 for the suction cleaner,both the cutting drill and the suction fan are placed in operation. Thecutting head of the core drill may then be pressed against the materialto be drilled in the usual manner.

Cuttings produced by drill teeth 21 are picked up by the low-pressurehigh-velocity airstream entering bore 46 exteriorly of the drill and arecarried rearwardly through barrel 15, openings 27, suction hood 39 andflexible hose 37 into the filter bag of suction cleaner 13. In thisconnection it will be understood that the low suction pressure existingwithin hose 37 is effective, in cooperation with the exterioratmospheric pressure, to hold hood 39 pressed tightly against flange 31of bushing 30. Since this bushing is journaled loosely about barrel 15there is no relative rotary movement between the bushing and suctionhood 39. Ribs 32 on the outer surface of the bushing serve to space thelatter from the rim edge and side walls of the bore sufficiently topermit an adequate stream of flushing air to flow into the bore aboutthe drill. It will be appreciated that in drilling certain materialslarger pieces may be dislodged which will not be entrained by theflushing stream. These may be removed periodically by withdrawing thedrill from the bore and clearing such pieces from the core barrel andfrom the bore. At this time it is convenient to break off the centralcore formed by the operation of the drill to facilitate further boring.

It will be recognized that core barrel 15 may be of any length dependingon the depth of the bore to be drilled. Accordingly, drills of variouslengths may be assembled by fitting the cutting head and the end cap tocore barrels of different lengths. For this purpose each barrel isprovided with identical tapered ends similar to ends 16 and 17 of thedescribed embodiment.

of the presently preferred embodiments of the invention 4- and that nolimitations are intended to the details of construction or design hereinshown other than as defined in the appended claims.

I claim:

1. Drilling apparatus adapted for drilling rock-like brittle materialsand employing a suction airstream to carry away cuttings therefrom to aplace of deposit, said apparatus comprising a core drill having adriving shank, a bushing loosely journaled about said drill and having aflange formed for support in spaced relation to the inlet rim of a borebeing drilled, means providing a suction air source independent of themotive means employed to drive said core drill and including a rimmedsuction hood communicating with the interior of said drill and havingits rim sealed against the flanged end of said bushing whereby thesuction airstream flows into the bore being drilled at a point beneathsaid bushing and picks up cuttings for removal centrally through saidcore drill and suction hood to a place of deposit.

2. Drilling apparatus as defined in claim 1 wherein said suction hood iscup-shaped and provided with an opening in its bottom fitting looselyabout said drill shank.

3. Drilling apparatus as defined in claim 1 wherein said suction hood iscup-shaped with a hole in its bottom loosely fitting said drill shank,said hood having a resilient rim adapted to seal against the surface ofsaid bushing when suction is applied to the interior thereof to providea stream of flushing air across the cutting teeth of said core drill.

4. Drilling apparatus as defined in claim 1 wherein said suction sourcecomprises a canister-type suction cleaner having a flexible hoseconnection with the interior of said suction hood, said cleaner beingoperable to produce a pressure differential across the walls of saidsuction hood effective to hold the same pressed firmly against the endof said bushing.

5. Core drilling apparatus for drilling brittle materials,

, said apparatus comprising an electric drilling motor having a drillchuck, a core drill having a rod-like shank detachably mountable in saidchuck, a tubular core barrel carried by said shank and having a ringprovided with cutting teeth across one rim end and being frictionallycoupled to the end of said core barrel by means of complemental nestingsurfaces, at flanged bushing loosely mounted for sliding movement alongsaid barrel and adapted to fit within the inlet of the bore beingdrilled, said bushing having provision for admitting a flow of flushingair into the hole about said barrel, a portable suction cleaning meanshaving a flexible hose provided with a suction hood, said hood having anopening fitting about said drill shank and an inlet end shaped to sealagainst the end of said bushing and to be held there by the operation ofsaid cleaner whereby the cuttings of said drill are carried away in ahigh velocity suction airstream flowing radially across the cuttingteeth and outwardly through said core barrel to a filter depositorywithin said suction cleaner.

6. Core drilling apparatus as defined in claim 5 wherein said suctionhood is formed of resilient material reinforced against collapse by wireloops embedded therein.

7. Core drilling apparatus as defined in claim 5 wherein the sealing rimof said suction hood includes a plurality of concentric flexible lips.

References Cited in the file of this patent UNITED STATES PATENTS1,084,152 Kessel Ian. 13, 1914 2,122,517 Curtis July 5, 1938 2,339,324Fischer Jan. 18, 1944 FOREIGN PATENTS 3,827 Great Britain Feb. 20, 1908

